Method of filtration.



I. H. JEWELL. METHOD OF FILTRATION. APPLICATION FILED 1 mm, 1997.

Patented Nov. 10, 1908.

INV TOR.

BY V Y A TTORN E145.

THE noRRls psrsm cm, WASHINW,1LI:.

-Method of Filtration,

"UNIT SA IRA H. JEWELL, OF

CHICAGO, ILLINOIS.

METHOD OF FILTRATION.

Specification of Letters Patent.

Patented Nov. 10, 1908.

Application filed February 4, 1907. Serial No. 355,550.

T 0 all whomit may concern:

Be it known that I, IRA H. J nwELL, a citizen of the United in thecounty of Cook and State of Illinois, have invented a certain new anduseful of which the following is a description.

My invention belongs to that particular method of filtration in whichthe fluid is caused to percolate through a granular bed, the filteredfluid being conducted therefrom in any suitable way, and in which meansare provided for cleansing the granular bed by a current of liquiddriven by pressure in a substantially reverse direction.

The object of my invention is to increase the effectiveness of filtersof this description. To this end my invention consists in the novelmethod herein described and more particularly pointed out in the claim.

In the drawings, wherein characters indicate like or parts,-Figure 1 isa fragmentary sectiona view of a well known form of filter, illustrating one means for carrying my method into operation; Fig. 2 is asectional view showing a modification; Fig. 3 is also a sectional viewshowing a further modification; Fig. 4 is a partial sectional view of aform adapted for either vertical or horizontal filtration.

In filters in which a granular bed is em ployed, which is washed by areverse current, it is found in practical use that the washing operationcarries the finer particles of the bed to the top thereof, where theyare deposited by the subsidence of the fluid after the washingoperation. Continued use of the granular material also tends to reducethe size of the particles of granular material, so that as a resultthere is formed upon the top of the bed a layer of very fine materialwhich extends in depth from a uarter of an inch to an inch or more,while be ow that the granular material is coarser and more porous. Thefine layer upon the top of the bed tends to retard the filteringoperation, and also tends to become clogged in a comparatively shorttime, depending upon the'quality of the liquid treated. This isparticularly true where a coagulant is used in connection with thefiltering operation.

The object of my present invention is to overcome the difficultiesreferred to by forming intercellular spaces in the body of the filterbed, and arranging to conduct a portion like reference correspondinStates, residing at Chicago of the fluid to said spaces. These spacesbeing positioned below the fine layer upon the top or bed, aidmaterially in the rapid filtration of the fluid, without in any wayinterfering with the operation of the fine layer upon the top of thebedin the ordinary manner. 1 is an outer tank having positioned thereinan k 2 spaced from the outer tank,

rovided with the usual connections to conduct fluid to and direct thesame away from aratus (not shown). 3 re resents the main body of thegranular be having upon its top a layer 4 of finer material, which iscaused to settle upon the top of the bed by the washing operationreferred to. At one or more points in the body of the bed, and below thefine top layer, I arrange a horizontal plate 5 provided with. downwardlyextending margins 6, and with a central pipe 7 connecting therewith. Thefluid is indicated in the drawing during the filtering operation, as at8. Gravity will cause the fluid to percolate through the bed, and aportion of it will pass through the space formed below the plate 5.space will be filled with liquid, as indicated, and, by reason of theweight of the column of water, and the action of gravity, will alsopercolate through the bed, and aid materially in the rapid operation ofthe device. The liquid will percolate through the fine layer above theplate 5, and will naturally find its way about the edges of the plate,and thus on to the outlet.

During the washing operation when reverse current is employed, he bed isagitated by the current, and the fluid passing over the top of the tank2 will pass down in the annular space between the two tanks and escapeby an outlet (not shown).

It is to be observed that the tube 7 should always be of suflicientheight so that the weight of the contained column of fluid shall not beless than the pressure of the reverse current. By this means the twopressures will be counterbalanced to such an extent that the granularbed will not enter the tube, and thus tend to clog the same. As shown,in Fig. 1, the tube 7 extends above the top of the tank 2, and thus theweight of the contained column of water will probably be slightlygreater than the pressure of the reverse current. t is obvious thatthese plates may be situated throughout the bed,

preferred number of them being emplo ed. It is'al'so' obvious that bythis means a bed of greater depth may be employed, thus materiallyincreasing the results of the operation of the device,

As shown in Fig 2, the plate '5 is not provided with the downwardlydepending marginal flanges 6, and the space below -the plate is thus ofslightly difierent form, it being the natural contour of the sand belowa plain herizehtal d sk plate- The ube 7 is employed in the same manneras before. In all ases it s o eu h heig tha the We g f the containedcolumn of fluid shall not be he then he pre sur of h e s r h employed ilWa hinghe shet h Fig- 3, th be 7 s shown w th p ura ity of. ehie h ede 9supp d h he tu th ap ur 10 form d beheath he hoods to ethtid, the r asdesired, any

Spa e .helew th he d, an thence per le e th ugh th be as bef dee rih d-I hi form o the der I pr f to mpl y ome uitehl f rm of va ve o p e entthe entrance f he ter al of e d into th pine, A show an eu we ly aringring 11 supported on the tube in proximity to the apertur s 10 and thevalve ring 12, le eely res s the eehhis he u tien Perm t e fl id to escp ut d f om he tub in o the pat beneat th he d, b w n the ve e eur eh imploye to a the bed th al e closes. an pre en s t e of any of the g anuar bed to e u e, and a he s m ti: h pre en s a y eur benea h the h ed,hie m ght ause t ather ng o eur fieieh quan i y of gr n l r material tointerfere with the operation of the device. v

As shown in Fig. 4, a space is formed at the side of the tank by meansof a hood 13', which preferably extends around the interior of the tank2, thus forming an annular space. The tube 7 extends through the wall ofthe tank 2 to connect with the space. This form is particularly adaptedfor either vertical or horizontal filtration, the operation beingsubstantially as before described in vertical filtration, while inhorizontal filtration fluid may percolate through the bed to a centralcore or cores, not shown, in the well known manner.

It is obvious that the cellular spaces re-.

ferred to may be located in such numher and at such points in the bed asdesired, or that two or more of the forms shown may be com bined'tosecure the desired results, As before remarked, with the method hereindescribed, a bed of much greater depth and capacity may be employed,thus greatly increasing the rate of filtration, without materiallyincreasing the cost. I i

What I claim as new and desire to secure by L tter a ent e A. methodof'filtering liquids which con sists of passing a portion of the liquidthrough a granular bed and in introducing another portion of the liquiddirectly to an interior portion of said bed and filtering it throughonly a portion of said bed.

In testimony whereof, sign d my n me scribing witnesses.

I ave he un o R Y W. HI CHARLES I. COBB.

in the presence of two sub-

